Here "lift up our hearts" represents praying sincerely. It was customary for the Israelites to raise their hands when praying to God. Alternate translation: "Let us pray sincerely with lifted hands" or "Let us lift up our hands and pray sincerely" (See: [[rc://en/ta/man/translate/figs-metaphor]] and [[rc://en/ta/man/translate/figs-metonymy]])